The article provides information about a new device, AlgaTox developed in the R&D project sponsored by the Technology Agency (n.TA02030179) and patented in Czech Republic (CZ 305687). Its functionality is based on the use of biosensor, and its main advantage is fast response rate. The toxicity detection is achieved through precise measurement of green algae oxygen production dynamics after their exposure to light of wavelength of 680 nm. Clark sensor with a resolution of 0.05% of the equilibrium oxygen concentrations and stability at a constant pressure and temperature of 0.1% of the equilibrium oxygen concentration at the 24-h measurement is used for the oxygen detection. Laboratory testing of the device has been made using silver nitrate, substance with known inhibitory effect on algae. Real samples of aqueous soil extracts and waste sample from old dried-up industrial tailing pond enriched with insecticide have been also tested. The values of oxygen production inhibition or stimulation determined with the new device in the evaluation of real samples were up to six times higher in comparison with the corresponding values of inhibition (stimulation) of growth rates determined by standard procedure.

The electrochemical oxidation (ECO) of carbamazepine (CBZ), an antiepileptic drug, has been carried out in this study. A response surface methodology approach (RSM) was used in order to optimize the treatment process for CBZ removal on synthetic effluent. Four different operating parameters (current intensity, treatment time, recycling flow rate, and anode type) were chosen as key factors while a single response (CBZ removal) was considered. In the first part of the study, a factorial design (FD) methodology was carried out in order to evaluate the effects and interactions between the selected factors. Results showed that anode type is the most important parameters affecting CBZ degradation (with 67% of the overall effect) followed by the treatment time, the current intensity, and then the recirculation flow rate. Subsequently, a central composite design (CCD) was conducted in order to optimize the overall process taking into account efficiency (CBZ removal) and energy consumption. The contribution of direct and indirect effects of CBZ electro-oxidation was also investigated. As expected, direct oxidation was the most dominant mechanism during ECO with approximately 66% whereas indirect oxidation contributed with only 12%. Finally, the determined optimal conditions were applied on real pharmaceutical wastewater. Despite the effect matrix, 84% of CBZ was obtained after only 100 min of treatment with 23% of mineralization. Finally, CBZ by-products such as salicylic acid, catechol, and anthranilic have been detected during the oxidation process.

Phytostabilisation can benefit from phytostimulatory rhizobacteria. Forty-three bacterial strains were isolated from the roots of the metallicolous legume Anthyllis vulneraria ssp. carpatica grown in a highly contaminated mine tailing (total Cd, Pb and Zn were up to 1200; 34,000; and 170,000 mg kg⁻¹, respectively). We aimed at evaluating their phytostimulatory effects on the development of leguminous metallophytes. Strains were screened for fluorescent siderophores and auxin synthesis, inorganic P solubilisation and 1-amino-cyclopropane-1-carboxylate deaminase (ACCd) activity to define a subset of 11 strains that were inoculated on the leguminous metallophytes A. vulneraria and Lotus corniculatus grown in diluted mine spoil (Zn 34,653; Pb 6842; and Cd 242, all in mg kg⁻¹). All strains were affiliated to Pseudomonas spp. (except two), synthetised auxins and siderophores and solubilised P (except three), and seven of them were ACCd positive. The inoculation effects (shoot-root-nodule biomass, chlorophyll content) depended on legume species and bacterial strain genotype. Phytostimulation scores were unrelated to siderophore/auxin synthesis and P solubilisation rates. Inoculations of the strain nos. 17–43 triggered a 1.2-fold significant increase in the chlorophyll content of A. vulneraria. Chlorophyll content and root biomass of L. corniculatus were significantly increased following the inoculations of the strain nos. 17–22 (1.5–1.4-fold, respectively). The strongest positive effects were related to increases in the nodule biomass of L. corniculatus in the presence of three ACCd-positive strains (1.8-fold), one of which was the highest auxin producer. These data suggest to focus on interactions between ACCd activity and auxin synthesis to enhance nodulation of metallicolous legumes.

The efficiency of phytoremediation is mainly dependent on the capacity of plants in absorption, translocation, and accumulation of Cd. This study was designed to investigate whether Cd translocation and accumulation in tall fescue plants was regulated by foliar application of KH₂PO₄. The results showed that the foliar application of KH₂PO₄ significantly increased Cd concentration and total Cd accumulated in leaves and the capacity of Cd extraction, compared to the root application. The water-soluble organic acid complexes and the pectate- and protein-integrated Cd were the two major Cd chemical forms deposited in leaves. The foliar application increased Cd in the pectate- and protein-integrated forms and decreased the water-soluble forms in leaves. Cd phosphates were not the major chemical forms deposited in leaves in both foliar and root applications. The results indicated that the foliar application of KH₂PO₄ enhanced Cd accumulation in leaves of tall fescue, which might be associated with the leaf deposit of the pectate- and protein-integrated Cd forms.

The aim of this work was to analyse the response of Rosa rubiginosa to salinity induced by different concentrations of sodium chloride and calcium chloride (0, 25, 50, 100, 150 and 200 mM). Besides salt accumulation and pH changes, other parameters were investigated including photosynthetic activity, leaf water content, the dynamics of necrosis and chlorosis appearance and leaf drying. The study was complemented with microscopic analysis of changes in leaf anatomy. R. rubiginosa was more sensitive to the salinity induced by calcium chloride than by sodium chloride. Plant response to salinity differed depending of the salt concentration. These differences were manifested by higher dynamics of necrosis and chlorosis appearance and leaf drying. CaCl₂ showed greater inhibition of the photosynthetic apparatus and photosynthetic activity. Treatment with CaCl₂ caused more visible deformation of palisade cells, reduction in their density and overall reduction in leaf thickness. The study demonstrated higher accumulation of CaCl₂ in the soil, and thus greater limitations in water availability resulting in reduced leaf water content and quicker drying of leaves as compared with NaCl-treated plants.

In tropical countries like Colombia, a large variety of available aquatic plants have yet to be investigated for phytodepuration processes. The aim of this study was to assess the effect of Cyper-us ligularis and Echinocloa colona¸ two local plants of Colombian Caribbean region, on removal of dissolved organic matter (COD) and nutrients (N-NH₄⁺, N-NO₃⁻ and P-PO₄⁻³) from domestic wastewater. Experiments were conducted in replicate pilot-scale Horizontal Subsurface Flow Constructed Wetlands (HSSF CWs) (0.66 m²). Four wetland treatment units were installed in parallel. Two were planted with C. ligularis and the other two remained with E. colona. The experimental system was connected to a 0.76-m³ primary sedimentation tank that fed experimental wetland treatment units. Wetlands were filled with granite gravel (~8 mm and 0.4 of porosity). During a period of 4 months, each treatment unit received a continuous loading at the rate of 42 L day⁻¹ and a hydraulic retention time of 2.3 days approximately. Wastewater samples from influent and effluents were collected three times each week in order to monitor temporal/spatial changes in removals efficiencies of COD, N-NH₄⁺, N-NO₃⁻, and P-PO₄⁻³. Results showed that removals of COD, N-NH₄⁺, and N-NO₃⁻ were not significantly different between treatments (p > 0.05). Nevertheless, P-PO₄⁻³ removal for E. colona was significantly higher than C. ligularis (p < 0.05), showing that this plant can assimilate important amounts of P. Further investigations must be conducted to evaluate the potential of native aquatic macrophytes for phytodepuration.

The aim of this study was to evaluate the redox mediating capacity of anthraquinone-2,6-disulfonate (AQDS) immobilized on granular activated carbon (GAC) during the reductive decolorization of direct blue 71 (DB71) under microbial and chemical conditions. The immobilization of AQDS on GAC was conducted by adsorption, and it has obtained an uptake capacity of 0.227 mmol g⁻¹. The anchorage of AQDS on GAC improved its electron transfer capacity (ETC) up to 2.05 times higher than the raw material. Similarly, the addition of GAC-AQDS increased up to 1.75- and 1.16-fold the rate of decolorization (k d) of DB71 under microbial and chemical conditions, respectively, in comparison to the unmodified GAC. Surprisingly, a higher k d value was achieved in incubations without either GAC or GAC-AQDS because of the generation of aromatic amines, from the reduction DB71, taking into account that these species may act as a catalyst in the DB71 reduction process. In contrast, adsorption of aromatic amines on either GAC or GAC-AQDS decreased its redox mediating capacity as evidenced by spectrophotometric screenings of the decolorized solution and the supporting material. The development of materials with enhanced both redox and adsorption properties, as the GAC used in this study, offers a promising way to increase the redox conversion of recalcitrant pollutants commonly found in industrial wastewaters.

Batch experiment at COD/NO₃ ⁻-N ratio of 8.0 was conducted to investigate the initial performance of the simultaneous denitrification and methanogenesis (SDM) process and corresponding granular sludge (SDMGS). The results showed a high level of inhibition of methanogenesis activity with nitrate addition, and the particle size, settling performance, and morphologies of the SDMGS were also different from conventional methanogenesis granular sludge. The structure and succession of bacterial communities of the granular sludge during the initial stage of the SDM process were determined using the high-throughput sequencing method. Sequence analysis indicated that diversity of bacterial communities was significantly decreased due to nitrate addition. Proteobacteria, Bacteroidetes, Firmicutes, and Spirochaetes were identified to be the dominant bacterial communities (96.06%) of the SDMGS samples, and microbes associated with anaerobic fermentation were reorganized. Alpha-, Beta- and Gamma-proteobacteria, and Bacteroides might be the sources of denitrificans. Lastly, species associated with animal and human infections, such as Enterobacteriaceae, Bacteroides, and other common human enteric pathogens, were found to be recovered during the initial stage. Short-term assessment of bacterial communities of the SDMGS would strengthen understandings of the effects of nitrate contamination in water bodies and provide vital guidance for operation of nitrate-containing wastewater treatment.

The progressive development of civilization and intensive industrialization has contributed to the global pollution of the natural environment by heavy metals, especially the soil. Degraded soils generally contain less organic matter, and thus, their homeostasis is more often disturbed, which in turn manifests in changes in biological and physicochemical properties of the soil. Therefore, new possibilities and solutions for possible neutralization of these contaminations are sought, inter alia, through reclamation of degraded land. At present, the use of additives supporting the reclamation process that exhibit heavy metal-sorbing properties is becoming increasingly important in soil recovery. Research was conducted to determine the role of compost in stabilizing the microbial and biochemical balance of the soil due to the significant problem of heavy metal-contaminated areas. The study was conducted on loamy sand, to which zinc was applied at the following doses: 0, 250, 500, 750, 1000, and 1250 mg Zn²⁺ kg⁻¹ DM of soil. Compost was introduced to the appropriate objects calculated on the basis of organic carbon content in the amount of 0, 10, and 20 g Cₒᵣg kg⁻¹ DM of soil. The study was conducted over a period of 20 weeks, maintaining soil moisture at 50% capillary water capacity. Zinc significantly modified soil microbiome status. The abundance of microorganisms and their biological diversity and the enzymatic activity of the soil were affected. The negative effects of contaminating zinc doses were alleviated by the introduction of compost into the soil. Organic fertilization led to microbial growth intensification and increased biochemical activity of the soil already 2 weeks after compost application. These effects persisted throughout the experiment. Therefore, it can be stated that the use of compost is an appropriate method for restoring normal functions of soil ecosystems contaminated with zinc.

Nanoparticles are among the particular materials produced by industrial activities; the release of these nanoparticles in natural ecosystems interacts with living organisms. Aquatic environment is the most common estuary waste medium for industrial and all human activities, the consequences may be highly effective on sea food species. Moreover, the potential in situ reduction of metallic ions by preexistent agents leads to nanoparticles which may cause hazardous effects. Many organisms become at risk especially those that use gills during respiration process such as bivalves. The study undertaken investigates the potential effect of silver nanoparticles obtained by green synthesis method on the gills of Ruditapes decussatus as a model. Nanoparticles have been synthesized using Ceratonia siliqua fruit extract as a reducing agent. The organisms have been chronically exposed to silver nanoparticles and the effects were biochemically evaluated. The tests performed show a typical behavior of catalase, glutathione reductase, and glutathione S-transferase activities that give information about the oxidative stress-induced malondialdehyde quantification, which reveals a possible membranous deterioration of the gills. Acetylcholinesterase expression has been qualified to be at a safe rate which implies the capacity of the animal to protect the cholinergic system.